1. Field of Invention
The present invention relates to holographic human-machine interfaces (“HMIs”) between humans and electronic or electro-mechanical devices.
2. Description of Related Art
There are many methods and devices available for entering data and commands into computers and other electronic equipment, such devices including, for example, keyboards, key pads, light pens, mice, pushbuttons, touch screens and trackballs. All of these input devices share a common feature: they require tangible physical contact by a user of the computer or electronic equipment. However, holographic HMIs involve no tangible physical contact between the human operator and the control elements of the HMIs because the input devices are holographic images of keys or other customarily touch-activated tangible input elements. Operator interaction with those holographic images is detected through electromagnetic means or other means, obviating the need for direct physical contact with any solid input object or surface.
Holographic HMIs between humans and electronic or electro-mechanical equipment are known in the art. Most notably, a “Holographic Control Arrangement” is described in U.K. Patent No. 2292711 (McPheters) and in U.S. Pat. No. 6,377,238 (McPheters), which are incorporated herein by reference.
Known holographic HMI systems may be characterized by the holographic HMI devices being relatively large and bulky, and they may consume relatively large amounts of power, making them impractical for some uses.
A problem may also occur with known holographic HMIs, when they are intended to replace touch screens or touch pads presenting multiple screens of information to the operator, because their holographic images cannot be smoothly integrated with input or output information available to the human operator on information presentation equipment of the electronic or electro-mechanical device being controlled.
In addition, a problem may occur when more than one piece of electronic or electro-mechanical equipment is controlled by holographic HMIs, requiring multiple holographic images. In such situations, an operator is easily distracted by the multiple images.
Another problem posed by present holographic HMIs is that, as compared with conventional interfaces, the operator of a holographic HMI receives no tactile feedback when interacting with a holographic HMI, which may cause the operator of the holographic HMI to lose track of the commands or information being entered into the electronic or electro-mechanical device.
Further, a problem may occur when the footprint of known holographic HMIs is not smaller than the physical dimensions of the conventional human-machine interfaces of the electronic or electro-mechanical device(s) being controlled.